Method for preparing magnesium hydroxide by using magnesium oxide

A technology of magnesium hydroxide and magnesium oxide, applied in magnesium hydroxide and other directions, can solve the problems of low hydration ratio of magnesium hydroxide, small magnesium hydroxide, and many impurities.

Active Publication Date: 2016-07-20
刘昕
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this method has disadvantages such as low yield and long washing cycle, and it is impossible to produce magnesium hydroxide with a small particle size.
Concentrated seawater extraction method, which uses concentrated seawater to extract slurry-like magnesium hydroxide, in which the existence of calcium ions is an important factor affecting

Method used

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  • Method for preparing magnesium hydroxide by using magnesium oxide
  • Method for preparing magnesium hydroxide by using magnesium oxide
  • Method for preparing magnesium hydroxide by using magnesium oxide

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Magnesium oxide with a measured calcium sulfate content of 0.61% by mass, produced from bischofite, was used. According to the ratio shown in Table 1, magnesium oxide, distilled water and barium chloride (with no addition of barium chloride as a control) were added and placed in a reaction kettle in a water bath at 50°C, stirred at a speed of 400 rpm for 6 hours, passed The liquid was filtered off by suction to obtain crude magnesium hydroxide. Then dry to constant weight (moisture content is lower than 1% by weight) at 50 ℃, make dry magnesium hydroxide, use 100 micron mesh sieve to sieve off residue, obtain final magnesium hydroxide product, and according to HG / The method described in T3607-2007 (issued on April 13, 2007, implemented on October 1, 2007) measures D50. The results are shown in Table 1 below as well as figure 1 middle.

[0032] Table 1

[0033] Barium Chloride: Calcium Sulfate Molar Ratio

[0034] From Table 1 and figure 1It can be seen t...

Embodiment 2

[0036] Example 2 was carried out in the same manner as in Example except for the contents shown in Table 2 below.

[0037] Table 2

[0038]

[0039]

[0040] From figure 2 combined with the results in Table 2 figure 1 It can be seen from the results that in figure 1 In the flat section where the molar ratio of barium chloride and calcium sulfate is 2:1 to 4:1, there is actually a "deep pit" between the molar ratio of 2.3:1 and 2.9:1. The D50 can be stably in the range of 0.5 to 1.0 micron, and a magnesium hydroxide product with a smaller particle size can be obtained by adopting the molar ratio in this range.

Embodiment 3

[0042] Example 3 was carried out in the same manner as in Example 1 except for the contents described in Table 3 below.

[0043] See Table 3 below for the results.

[0044] table 3

[0045]

[0046]

[0047] Note:

[0048] (1)*The mass fraction of the sieve residue refers to the mass percentage of the material that does not pass through the 75-micron mesh when sieving with a 75-micron test sieve to the entire material.

[0049] (2) The mass fraction of sieve residue and D50 are carried out according to the method stipulated in the industry standard of HG / T3607-2007 (issued on April 13, 2007, and implemented on October 1, 2007), in which the mass fraction of sieve residue is Class II The standards for first-class and qualified products are less than or equal to 0.02% and less than or equal to 0.05% respectively; the standards for Class III first-class products and qualified products are respectively less than or equal to 0.5 and less than or equal to 1.0. The D50 Class...

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Abstract

The invention provides a method for preparing magnesium hydroxide by using magnesium oxide. The method comprises the following steps: obtaining magnesium oxide and determining the content of calcium sulphate in the magnesium oxide; preparing paste with magnesium oxide by using distilled water, adding barium chloride to the paste, and performing stirring under the temperature of 45-55 DEG C at the speed of 400-500r/m for 6-7 hours so as to enable the magnesium oxide and the distilled water to be subjected to a reaction; then filtering out liquid so as to prepare crude magnesium hydroxide; drying the crude magnesium hydroxide under 45-55 DEG C until the water content is lower than 1wt%, so as to prepare dried magnesium hydroxide; sieving the dried magnesium hydroxide with a mesh screen of which the bore diameter is 200 microns or below, and removing coarse particles, so as to prepare the magnesium hydroxide with small particle diameters. Through the adoption of the method, the magnesium oxide can be directly used for preparing the magnesium hydroxide which is high in yield and of which D50 is smaller than 1.0 micron without any post treatment.

Description

technical field [0001] The invention relates to a method for preparing magnesium hydroxide by using magnesium oxide. Background technique [0002] Magnesium hydroxide is also called caustic magnesia, light burnt magnesia, etc., and the suspension of magnesium hydroxide in water is called magnesium hydroxide emulsion, or milk of magnesia for short. Magnesium hydroxide is a colorless hexagonal prism crystal or white powder, hardly soluble in water and alcohol, soluble in dilute acid and ammonium salt solution, and its aqueous solution is alkaline. Density of magnesium hydroxide (g / mL, 20°C): 2.36; melting point (°C): 350; refractive index (n20 / D): about 1.57. [0003] Magnesium hydroxide has a wide range of uses and is an excellent flame retardant for plastics and rubber products. It is currently recognized as an excellent flame retardant with triple functions of flame retardancy, smoke suppression and filling in the rubber and plastic industry. In terms of environmental pro...

Claims

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Application Information

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IPC IPC(8): C01F5/14
CPCC01F5/14C01P2004/61C01P2004/62
Inventor 姚胜铎
Owner 刘昕
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